Preheat your oven to 400°F (200°C). This high temperature will help the chicken and vegetables roast nicely.
In a large mixing bowl, combine the chicken thighs, red bell pepper, yellow onion, broccoli florets, and snow peas. Drizzle the olive oil over the mixture, and sprinkle with salt, black pepper, garlic powder, and ground ginger. Toss everything together until well coated.
Spread the chicken and vegetable mixture evenly on the prepared sheet pan, arranging the chicken pieces skin-side up for maximum crispiness.
Place the sheet pan in the preheated oven and bake for 20 minutes. Then drizzle half of the teriyaki sauce over the chicken and vegetables, return to the oven and bake for an additional 10-15 minutes.
Once done, drizzle the remaining teriyaki sauce over the top and let it sit for a few minutes to absorb the flavors.
Garnish with optional sesame seeds, green onions, or fresh herbs if desired. Serve hot with steamed rice or quinoa.